From ff6484ba8caa9f1e8484da1ca9bf9ded2fc99c02 Mon Sep 17 00:00:00 2001
From: sapics <gv.nishino@gmail.com>
Date: Thu, 16 Jun 2016 14:37:07 +0900
Subject: [PATCH] Fix to cover the case when Numerical.solveQuadratic return -1
 in Numerical.solveCubic

---
 src/util/Numerical.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/util/Numerical.js b/src/util/Numerical.js
index 44050fbb..b81718d8 100644
--- a/src/util/Numerical.js
+++ b/src/util/Numerical.js
@@ -356,7 +356,8 @@ var Numerical = new function() {
             }
             // The cubic has been deflated to a quadratic.
             var count = Numerical.solveQuadratic(a, b1, c2, roots, min, max);
-            if (isFinite(x) && (count === 0 || x !== roots[count - 1])
+            if (isFinite(x) && count >= 0
+                    && (count === 0 || x !== roots[count - 1])
                     && (min == null || x > min - EPSILON && x < max + EPSILON))
                 roots[count++] = min == null ? x : clamp(x, min, max);
             return count;